Conventionally, polysilanes are synthesized by using as a raw material a silicon compound having chlorine atoms and carrying out the Wurtz-type condensation reaction in the presence of an alkali metal. However, in such a process for the synthesis of polysilanes, the reaction proceeds violently and thus it is difficult to control. In addition it is required to use an alkali metal, whose risk of ignition is high and whose handling is difficult, in an amount of at least twice as much as the mol of the silane compound monomer. Further, a trace amount of chlorine remains in the produced polysilane, leading to such problems as lowering of the electroconductivity.
In relation to the above, recently processes for the synthesis of polysilanes are suggested wherein a hydrosilane is subjected to dehydrogenative condensation in the presence of a complex of a transition metal, such as rhodium, iridium, ruthenium, palladium, platinum, cobalt, nickel, titanium, zirconium, and hafnium (described in, for example, Japanese Patent Application (OPI) No. 198631/1989; Chemistry Letters, 1989, page 83; and ACS Symposium Series, Vol. 360, page 89, 1988, published by the American Chemical Society). However, there are still problems that, for example, the catalyst activity is low and the amounts of by-products are large, and therefore it cannot be said that these processes are industrially satisfactory processes. On the other hand, in recent years, attempts to use, instead of a transition metal complex catalyst, a complex of lanthanoid metals in a catalytic reaction are being energetically made. However, only a few reactions are reported wherein the catalyst activity is recognized such reactions as for hydrogenation and ethylene polymerization.